Insight into feeding behaviour of first amphibians

Apart from its role in the world of structures, machines, and pure technology, engineering can also make a valuable contribution to other disciplines. Jordi Marcé-Nogué, a researcher with the Laboratory for the Technological Innovation of Structures and Materials (LITEM), located on the UPC's Terrassa Campus, has worked with researchers at the Miquel Crusafont Catalan Institute of Palaeontology (ICP) to learn about the feeding behaviour of the first vertebrates to develop limbs and digits: early tetrapods, which included the first amphibians.

Pioneering technique

Marcé-Nogué, an expert in computational mechanics, which combines numerical calculus and computer simulation, has applied the techniques of this discipline to help a team of ICP biologists led by researcher Josep Fortuny learn about the feeding behaviour of these arthropods. Techniques employed in the reconstruction of medical images were used to obtain geometric data on the skulls for digital processing. These data were then used with a finite element code to simulate the structures of the animals, particularly their skulls. The analysis allowed the researchers to compare skull models proposed by palaeontologists and study their stress and displacement fields. This is the first time a system of this kind has been used to study the earliest basal tetrapods.

The results obtained by applying this technique enabled the researchers to quantify differences in form between fossil skulls of temnospondyls, an extinct but once abundant order of tetrapods whose fossil remains are found worldwide. When the researchers compared these data with the biomechanical data, they found a clear correlation between the form of the skulls and their mechanical properties. Based on these findings, the ICP concluded that the feeding behaviour of temnospondyls was similar to that of present-day crocodiles; the animals caught their prey and bit their victims directly. Some species fed in a manner more similar to present-day gharials (crocodiles with long, slender snouts), preying on fish and small aquatic organisms.

Variety of feeding behaviours

The study on the skull morphology of these tetrapods has shown that they engaged in a wide variety of feeding behaviours: some fed exclusively on aquatic species; others were amphibious feeders; and some were adapted to terrestrial feeding.

The technology, dubbed iTesTiT, is based on five Catalan patents and has led to the formation of a spin-off.